1. Click on Security.
2. Click the Certificates link.
3. Click the Install link next to Install/Renew Certificate.
4. Click the Add New Certificate button at the bottom of the screen.
5. Copy the certificate along with the private key and paste them into the appropriate boxes.
a. First Box: Paste the contents of the certificate in PEM format. This is the plain-text version of the whole yourDomain.crt file.
b. Second Box: Paste the contents of the RSA Private Key in PEM format. This is the plain-text version of the key file that was generate earlier.
c. Password Box: if you provided a password when generating the CSR, enter it now.
d. Third Box: Paste the contents of the ca-bundle file in PEM format. This is the plain-text version of the whole yourDomain.ca-bundle file.
6. Click the Go! button.
You will now be returned to the SSL Server Certificate installation screen and you should see your newly installed certificate.